I have two instances of Bitbucket Datacenter in two different datacenters. Both nodes are Linux with 6 cpus and 16 GB memory. One instance is very fast thru the UI the other about a month ago got very slow after login. You click a project or any admin item and it takes 4 seconds to respond. Prior to login it is as fast as the other instance. It is very strange. The database is Oracle 12c. I tried RDP to another server to eliminate my box and it is the same.